Pile fabric and method of treating same



Apnl 12, 1955 s. M. KINZINGER ETAL FILE FABRIC AND METHOD OF TREATING SAME Filed June 4, 1953 HEHT (014.5 J

7mmmmummmmmmmmmmmmmlmw A frog/v5 Y5 2,7 05,889 PILE FABREfiAND METHOD 9F TREATING SAME Siegfried as. Kinzlnger and John P. Malik, Delavan, we, assignors to The George W. Borg Corporation,-Delavan,' Wis, a corporationof Delaware Application June4, 1953, Serial No. 359,614

1i Claims. ((166-491) This invention relates to improvements in pile fabrics.

Pile fabrics, with which. this invention is concerned, may be generally defined as those fabrics which include a-base fabric, knitted or woven, and a pile made up of fibers so interlaced, enmeshed and interlocked with the base fabric as to be securely held and extended from a surface of the base fabric. In some pile fabrics, the pile has the appearance of fur. Especially where the base fabric is knitted, the fabric is very elastic and has What is termed a soft back which makes the fabric unsuited for many of its potential commercial applications, not only because of excessive stretching characteristics, but also because the fibers of the pile tend to become loosened during the use of the fabric.

Excessive stretchability and shedding. of knitted pile fabric has been avoided in the past by the application of a'coating to the basefabric. The coatings have comprised a number of different materials but they usually include rubber-like material. Many of them include latex, the application of which to the base fabric has been accompanied by impregnation of the base fabric fibers and the embedding of the pile fibers. This insures that the pile fibers are permanentlybonded to the base fabric.

it has been found that coating has eliminated to a marked degree the softness of the whole-fabric and substantially reduced the draping qualities. Attempts to preserve a sufficient softness and to preserve adequate draping qualities for some purposes have until now defied the researcher.

The object of the invention is to provide a pile fabric having a predetermined stretchability and a predetermined softness and draping quality.

More particularly stated, it is an object of this invention to provide a new pile fabric product comprising a combination of materials in a base fabric and pile fabric offering characteristics of softness and draping qualities without the necessity for a'coating of the base-fabric and without objectionable stretchability or shedding.

The invention further involves a novel method in the manufacture of pile fabric whereby to obtain the objec-' tives of softness, predetermined stretchability, and good draping qualities.

In the drawings:

Fig. 1 shows somewhat diagrammatically a vertical section through a pile fabric knitted of materials in accord with the invention.

Fig. 2 is a view similar tol ig. l'and showing the same pile fabric after it has been processed in accord'with the invention.

Fig. 3 is a view similar to Fig. 2 but'showinga pile fabric in which the base fibers are cotton or wool and the pile fibers of thermoplastic are shrunk to bind the unshrunk. base fibers.

Pig. 4 is a diagrammatic disclosure of the steps followed in the method of treating the pile fabric shown in Fig. 2.

Fig. 5 is a section on line 55 of Fig. 4.

A' base fabric 19 knitted or woven from a yarn or filament comprising oriented thermoplastic fiber instead of the usual cotton thread or woolen yarn is subjected to heat or to a solvent or a combination of both heat and solvent with the result that the fiber is set or shrunk/to.

obtain the improved physical characteristics referredto above. By thermoplastic fiber is meant such products as polyvinylchloride or'copolym'ersof'vinyl chloride Patented Apr. 7 12, 1955.

and such fibersas. are marketed'under the trade names Vinyon, dynel, saran, and polyethylene'fibers;

A thermoplastic,.oriented fiber is made from a'plastic material that softenszwith heat'andwhich, after. spinning or extruding is stretchedtovarious degrees in' orderi to align itsmoleculartstructure :andimp'rove itsphysical properties. Subjectingsuch' fibers to heat or'solvents' causes them to deorient iorshrinktbackito their natural form or size and this processcan: be controlled .by' thedegree of heat applied 'to :those evarious "fibers.-

The 'knittingprocess and" the provision'zof pilezfibers" is carried on in the same way: that pile ifabricais made.

under the disclosure in Patent No. 2,630,619.v Thisinvolves the knitting into the-'basefabric'10 of pilefibers 11 which are looped about the yarnv 12 so that the ends 13, 14 of the pile fibers extend outwardly from theuppersurface of the base'fabric. If.the stitch:for the'base fabric is relatively tight, the pile fibers 11 are tightly held,

but even then the normal flexing of the base-fabric will cause the pile fibers 11 to work loose from their looping:

engagement about the yarn 12 and shedding of thepile fibers would normally result from. theme of the pile fabric. Increased tension upon the yarn asit goes through the knitting process would hold the fibers 11 more tightly, but the resultingfabric would be boardy and woud not have good drapingcharacteristics.

Under the process of the instant invention,apile fabric 15 is knitted with what would be considered a'medium stitch so far as tightness is concerned, and since the base fabric 19 is knitted of an oriented thermoplastic fiber, it has been found possible'afterthe knitting process'is'complete to apply a heat treatment or a-solventi treatment to shrink or set the fibers orvyarn 12 with .resultant desirable physical change" of the knitted "base or'back'.

As shown in the drawing, the pile fabric 15.is applied to the equivalent of a'"tenter frame? in this case comprising a pair of spaced conveyor-like belts 16 and 17 having upstanding; pins 18 upon which the marginal portions of the web of fabric areirnpaled. The belts 16 and 17 are mounted upon pulleys 19' and 2f); the-pulleys 19 being spaced apart so that the belts'16 and 17 have an. interval the same as the normal unstretchedtwidth of the web of pile fabric 15. Guides 21 and 22 for the belts diverge so as to separate the belts more widely'and the plastic yarn or fiber'in its-base fabricis applied-ate the pins of the spaced belts 16- 47 and,. in'the;advance of the web,- it is stretched'laterally: The web. is stretched longitudinally as the Web is applied to the pins 18. Then. as the stretched web yis'advanced upontthe-belts:16-17 under or through oven'25, heat is'applied IOthfiflllldGI' surface of the pile fabric. The heat is substantially excluded from reaching the. pile fibers 11:. Preferably-thepile fabric is applied to the pins 'onthe.beltsr1617 with the pile fibers on the under side'and'the, yarns or fibers of the base fabric aresexposed on the upperside whilethe material advances through the oven 25; It isfithus POS'. sible to have ,a source'of-heat such as infra-red rays-Ia diantly directed downwardly upon the base fabric toac complish the setting or shrinkage of: the base fabric fibers without applying an objectionableamountofcheat to the pile fibers 11.

The degree of heat treatment-both in terms of tem: perature and time is important. treatment to produce a required result for: pile fabric to. be used in differing commercial uses will differ considerably. We therefore wil describe'here' anrexample in which the ultimate product is a pile fabric suitablefor the clothing trade-as for instance in -the manufacture of fur coats where a material of good flexibility and good. draping eflect is required.

in this example, the base fabric islknittedfromadynel and the pile fibers are an approximatediameter of from- The pulleys 20 are spaced apart'more Also theamount of heat perature of 290 F. while traveling at two and one-half yards per minute. The speed of operation of the belts 1617 is such that any particular portion of the web of pile fabric is in the oven four minutes. It is to be understood, of course, that the oven may be at a higher temperature if the speed of the belts is increased so that the material is heated for a lesser time.

Examination of the treated material 26 following the process as described in the example above shows that the excessively stretchable untreated fabric 15 (Fig. l) which would be rejected for most uses in the clothing trade has now acquired characteristics of dimensional stability, the good draping qualities have been retained and any objectionable tendency of the pile fibers to be released from the base fabric is gone. The examination of the treated fabric 26 discloses the reasons for the change in characteristics.

When the base fabric yarn or filament undergoes the heat treatment described above, physical changes tak place, most important of which are shrinkage and kinking. It appears that this shrinkage is accompanied by a crinkling or kinking of the fibers and the combination of the shrinkage and the kinking is believed to have a major influence in setting the product 26 (see Fig. 2). Also the pile fibers are more closely bound and more definitely retained by the base fabric as a result of the heat treatment. It will also be noted that after this treatment one fiber will have been creased into another, but no welding of the fibers has taken place.

If, as shown in Fig. 3, the base fabric comprises fibers which are not particularly subject to shrinkage and kinking under heat or solvent treatment, the base fabric will maintain its status during such treatment as shown by comparison of the disclosure in Fig. 3 with Fig. 1. And if with such base fabric as cotton or wool 30, pile fibers 11 comprise thermoplastic treated as shown in Fig. 3, the. kinking and contraction resulting from the treatment will cause the pile fibers 11 to bind tightly about the unshrunk base fibers.

As is well known in the art related to thermoplastic fibers, a certain degree of shrinkage and kinking of the fibers can be obtained by exposing them to an atmosphere of vaporized solvent. Solvents to achieve this purpose for the above named fibers are compounds containing keto groups such as methylethylketone or methylisobutyll ketone or other higher boiling ketones. Referring to the steps of the process as diagrammatically set forth in Fig. 4; an atmosphere of solvent vapor or spray in place of the oven applied to the surface of the base fabric opposite the pile will shrink and kink the base fabric fibers with approximately the same result as that described in the example above.

Of course, if the pile fibers 11 are filaments or yarn comprising one of the thermoplastics responsive to heat or solvent treatment, it will be understood that they will likewise,'to the extent to which they are exposed to the heat or solvent, shrink or kink so as to oifer holding power and greater stability for the complete fabric.

' It has been found in the research and tests incident to the development of this invention that steam treatment in the oven 25 coincident with the application of oven heat from other sources assists in the shrinking of thermoplastics, dynel in particular. On the other hand, it has been found that the application of heat directly to the base fabric by passing the base fabric directly in contact with a hot calender roll' is effective in carrying out the invention.

It is possible by applying heat to a thermoplastic base fabric for a'longer period of time or with a somewhat higher heat to so shrink the base fabric as to make the product boardy, but to one skilled in this art it is readily possible to gauge the heat, the time of heat treatment and the degree to which the heat will permeate the base fabric to arrive at a satisfactory end product 26 suitable for the .commercial requirements to which the process is gauged.

Also under certain circumstances, it may be necessary to apply a fairly high heat, for instance 375 or even 380 F. for dynel or a slower rate of passage through the oven in order to accomplish a particularly difficult tightening of base fabric and pile, and if as a result of such more severe treatment a boardy effect results, the end product26 may be treated as by perching to remove some of the boardy effect.

A pile fabric, heat-set in accord with the above disclosure, has an appearance as to the back or non-pile surface which for many purposes might be deemed unfinished. In fact it is usually expected to be covered with some type of lining. We have found, however, that this back surface after heat-setting is admirably adapted to a napping or brushing treatment, the result of which is to finish the surface adequately so that it has a dressy appearance. It may be left exposed as the inner surface of a garment without requiring any lining, and, of course, in the many uses of this heat-set pile fabric, as for instance for robes, it is a complete product.

We claim:

1. The method of stabilizing a pile fabric of thermoplastic base fibers intertwined with pile fibers with the pile fibers extending outwardly on the front side of said fabric comprising the steps of treating said pile fabric only from the back side thereof to release the internal stresses in the fibers thereof and simultaneously placing said base fabric under tension, while protecting the outwardly extending portions of the pile fibers.

2. A pile fabric including thermoplastic base fibers and pile fibers intertwined with said thermoplastic base fibers, said pile fibers extending outwardly on the front side of said pile fabric, wherein the pile fabric is treated only'from the back side thereof to release the internal stresses in the fibers thereof and the base fabric is simul taneously placed under tension while the outwardly extending portions of the pile fibers are protected.

3. The method of treating a pile fabric comprising a base fabric including thermoplastic fibers shrinkable under heat treatment and pile fibers enmeshed therewith and extending outwardly from one surface thereof, said method including the steps of placing the base fabric under tension and heat treating said pile fabric from only the side opposite of the outwardly extending pile fibers to shrink said thermoplastic fibers while the outwardly extending portions of said pile fibers remain unaffected.

4. A pile fabric comprising a base fabric including thermoplastic fibers shrinkable under heat treatment and pile fibers enmeshed therewith and extending outwardly from one surface thereof, wherein said base fabric is placed under tension and wherein said pile fabric is heat treated from only the side opposite of the outwardly extending pile fibers to shrink said thermoplastic fibers while the outwardly extending portions of said pile fibers remain unaffected.

5. The method of treating a pile fabric comprising a knitted base fabric including thermoplastic fibers and pile fibers enmeshed with the base fabric, said method'including the steps of stretching said base fabric and applying a physical shrinking treatment to the base fabric 'and to the enmeshed portions of the pile fibers only while maintaining the base fabric in stretched condition and leaving the outwardly extending portions of said pile fibers substantially unafiected.

6. A pile fabric comprising a knitted base fabric including thermoplastic fibers and pile fibers enmeshed with said knitted base fabric, wherein said base fabric is stretched and a physical shrinking treatment is applied to the base fabric and the enmeshed portions of the pile fibers only while the base fabric is maintianed in stretched condition, and wherein the outwardly extending portions of the pile fibers are substantially unaffected.

7. The method of treating a pile fabric comprising a knitted base fabric including thermoplastic fibers and pile fibers enmeshed with the base fabric and extending outwardly from only one side of said base fabric, said method including the steps of stretching said base fabric,'and simultaneously applying a physical shrinking treatrnent to said base fabic and the enmeshed portions of the pile fibers only while simultaneously protecting'from such treatment the portions of pile fibers extending outwardly from said one side.

8. A pile fabric comprising a knitted base fabric including thermoplastic fibers and pile fibers enmeshed with said base fabric and extending outwardly from only one' side of said base fabric, wherein said base fabric is stretched and a physical shrinking treatment is simultaneously applied to said base ,fabric and to the enmeshed portions of the pile fibers only while the portions of said pile fibers extending outwardly from said one side are protected from such treatment.

9. The method of treating a pile fabric comprising a knitted base fabric including thermoplastic fibers and pile fibers including thermoplastic fibers enmeshed with said ltri'glsebfabrifqbsaid melthod 1includinghthe s'ieplslr of kstretching References Cited in the file of this patent e ase a ric, an app ying a p ysica s in g treatment to the base fabric and to that portion of the pile UNITED STATES PATENTS fibers only enmeshed with the base fabric while main- 1,912,625 Dreyfus June 6, 1933 taining the base fabric in stretched condition and leaving 5 2,035,641 Dickie et at Mar. 31, 1936 the outwardly extending portions of said pile fibers sub- 2,238,098 Bradshaw Apr. 15, 1941 stantially unafiected. 2,434,111 Hawley et a1. Jan. 6, 1948 10. A pile fabric comprising a knitted base fabric in- 2,574,200 Teague Nov. ,6, 1951 eluding thermoplastic fibers and pile fibers including ther- 2,591,861 Pannaci Apr. 8, 1952 moplastic fibers enmeshed with said base fabric, wherein 10 2,630,619 Schmidt et a1. Mar. 10, 1953 said base fabric is strteltchted afntlij a phgl sicatlh shrinking 2,639,488 Stanley et a1 May26, 1953 treatment is app ie to e ase a ric an to at portion of the pile fibers only enmeshed with said base fabric FQREIGN PATENTS while the base fabric is maintained in stretched condition 644,804 Great Britain Oct. 18, 1950 and the outwardly extending portions of said pile fibers 15 are left substantially unaflected. 

